By: Ryan Zeng and Rachel Gunawan

Geothermal Energy

Geothermal energy is an environmentally friendly way of producing renewable sources of initial energy. This process reduces the use of fossil fuels, which brings pollution to this earth. Geothermal power plants are set up around the world and is commonly used in most countries.

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The Geothermal Energy Process
The Geothermal Energy Process

How does it work?


Resources such as boilers, turbines/ generators, water, and pipes leading to the magma area are used in the process of geothermal energy. During the first stage of this process, the ground is drilled down deep enough to where magma is located. This has to be where the earth's crust is thin and is mostly done along the Pacific Rim, where deep fractures occur in the earths crust. This is done to connect the pipes underground to where the magma is located which is the first energy source in the whole process and is called thermal energy. Water is then pumped down from a boiler and down into the pipes to the area when it is heated by the magma. From the intense heat of the magma, the water then transforms into steam which then spins a turbine from underneath. This energy slowly transforms into kinetic energy. From a large magnet in a wire of coil that spins in an electric generator an electric current is generated and it get evenly distributed through electrical wires leading to towns and cities. Although this is the basic way setting up a geothermal power-plant there are three different kinds of the power-plant. The first one is known as the flash steam power plant and they operate by using tanks of water with temperatures greater than 360 degrees Fahrenheit. As water goes up through wells that are in the ground under its own pressure, the pressure decreases and some hot water flashes into high-pressure steam. Then the steam is used to spin a turbine to create electricity and the leftover water from the condensed steam flows back to the place where they store water known as the reservoir. The second kind of a power-plant is called the dry-steam power-plant. The only difference is that the dry steam power plants depend on water drawn from underground and its the same process with steam turning the turbine to create electricity. The third kind of power-plant is known as the binary-cycle power plants. These power plants work by using water with temperature lower than 225 degrees to 360 degrees Fahrenheit. The heat energy is used from the hot water to boil the other sources of water. The water would be vaporized in a heat ex-changer and used to spin the turbine. Then the water travels back into the earth to be reheated. These are the three different kinds of power-plants.

The Binary Cycle Power Plant
The Binary Cycle Power Plant

Dry Steam Power Plant
Dry Steam Power Plant

The Flash Steam Power Plant
The Flash Steam Power Plant

How widespread is this whole process?

Geothermal power-plants are setup in 23 countries (Armenia, Australia, Canada, Chile, China, Denmark, El Salvador ,Germany, Iceland ,Indonesia ,Japan, Kenya, Lithuania, Mexico, New Zealand, Portugal, Philippines, Romania, Russia, Turkey, United Kingdom, United States, West Indies), around the world and six countries in Africa (Kenya, Dijibouti, Uganda, Tanzania, Eritrea, Uganda). This process of producing energy only provide about 0.416& of the world wide energy and is the fourth largest renewable energy, The reason why Geothermal pants aren't that widespread is because of the fact that it has limited locations where the earth's curst is thin and those are the only places where geothermal power plants can be setup.

Geothermal Energy vs The World
Geothermal Energy vs The World

The efficiency of this process

Geothermal power-plants send out about 28 gigawatts of direct geothermal heating, 10,715 megawatts of geothermal energy online, and 67,246 megawatts of electricity. Only one power-plant provides about 1-50 megawatts of electricity to surrounding cities and towns and that says that geothermal can't provie much electricity. One of the reasons why geothermal energy is not used much around the world even though it is very eco-friendly is because it is very expensive to build and provide all necessary materials needed for this process. Countries spend about $20 million for each well, and $5 million per 2.5 mile drill.
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What are the benefits and drawbacks of this method?

The method of geothermal is mostly considered an eco-friendly method instead of having drawbacks. Although there are some drawbacks on this method it is still one of the cleanest method of producing electricity.
Benefits of this method:
  • environmentally friendly / reduces the use of fossil fuels
  • significant cost saving / save up 80% costs over fossil fuel
  • creates new jobs for local people
  • renewable source of energy
  • sustainable and reliable
  • power plants require little land
Drawbacks of this method:
  • digging can send off carbon dioxide
  • produces waste water which can damage the soil
  • expensive to generate - high installation costs
  • many run out of steam
  • not sustainable to all buildings
  • can lead to earthquakes from digging
  • needs antifreeze so water won't freeze at times
  • geothermal power can only be used where Earth's crust is thin.

Role In The Future

In our opinion we think that the process of geothermal has the potential to be more widespread in the future. The process of geothermal will be more widespread of expanding in range and size of resources. Energy from this process is renewable and is limitless resulting in a reliable source of energy although it has limited locations for this to be set up because it can only be used in areas where the Earth's crust is thin. We believe that maybe in the future to make the process more efficient locals would add an upgrade such as the hydroelectric power to the process of geothermal power. The energy created between these two sources will increase in a result of more electricity being produced. There are no negatives to this process because both of these two processes are nature friendly and can be easily combined. Also, the technology would evidently improve during the next few years and better technology would be added to the process of geothermal making it more efficient. There will be a time when the population would expand way beyond and the use of fossil fuels will have to decrease. This is our opinion about what we think about the role of geothermal in the future.

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Bibliography~
http://www.renewableenergyworld.com/rea/tech/geothermal-energy
http://en.wikipedia.org/wiki/Geothermal_energy
http://exergy.se/goran/cng/alten/proj/98/geotermal/geo.htm#_Toc492881535
http://www.newworldencyclopedia.org/entry/Geothermal_power
http://exergy.se/goran/cng/alten/proj/98/geotermal/geo.htm#_Toc492881535
http://www.ecomagination.com/five-questions-on-geothermal-energy-in-africa
http://www.webmutations.com/energy/reports/present/repgeo.html
http://www.efficiencyresource.org/Images/renewable/geo_binary_cycle.png
http://www.ourplanet.org.uk/other-renewable/drysteam.gif
http://teeic.anl.gov/images/photos/Geotherm_Schematic2.jpg
http://www.grinningplanet.com/2005/07-12/heinberg-3-450.jpg
http://upload.wikimedia.org/wikipedia/commons/c/c4/Geothermal_energy_methods.png